The present invention concerns communications utilising optical fibres as an information vehicle and more particularly optoelectronic conversion devices necessary at the ends of the optical fibre cable.
The existence of cables comprising a number of independent optical fibres, such as those described in U.S. application Ser. No. 18, 269, filed Mar. 7, 1979, and assigned to the same Assignee as the instant application necessitates multi-access signal conversion devices for simultaneously processing the signals carried by each of the optical fibres in the cable. In order to fully grasp the problem reference is made to FIGS. 1a and 1b which show transverse and longitudinal sections, respectively, of a cable element described in the aforesaid Patent application. It consists of a central metal core 1 surrounded by a dielectric star profiled sheath 2 formed with helical grooves 4 of V-shaped profile, which in extruded onto core 1. After the optical fibres 6 have been laid in the grooves 4, a taping 5 closes the grooves. The optical fibres 6 are allowed sufficient freedom to avoid stresses which are likely to cause attenuation. When the cable is limited to one element, it is protected by an envelope and sheating 7.
The present invention has for its object to provide a signal converter which is matched to a cable of the type just described.